Working on a very basic game, and I need some help

Hello everyone. I am very new to C++ (only been at it for a few days) and I am making a very basic text based fighting simulator.

I've run into numerous problems, but for the most part, I've solved them through trying different things. However, right now I am stuck and I haven't been able to solve it myself.

Basically I have a function for the "Arena", a class for the player named Fighter, a class for the monster/enemy, and a few others. In the main() function a switch statement is called with difference options like attack, block, and stuff like that. Selecting the attack option calls an attack() function in the Fighter class, which is where damage is calculated based on the players/enemy's strength ( I plan on making this more complicated in the future). The "damage" is then returned and then applied the the player/enemy's health.

The problem I am having right now is that the damage is not getting applied to the players health. It is doing the "damage" calculation in the attack() function because it reads it out with a cout, but once it gets returned back, it won't apply it to the players health. I hope I have explained this well enough, although I'm sure for most members here it's very easy to see what is happening just from looking at the code.

Here is an image of the program running. http://imgur.com/RTWSZ As you can see, it is running fine, and it even reads out the appropiate damage, but then you will notice it doesn't actually apply the damage variable to the m.health variable. It goes completely through the program as it is intended as well.

Ah, thank you so much! So the problem before was what? I see now, that I wasn't returning the right variable. Specifying return a.attack() will return givDamage because I specified "return givDamage;" in a.attack correct? So what was I returning before? Was it just the x variable in the arena() function, which was 0? Thanks again! :)

P.S. Is there a way to ensure an int never goes below zero? So if int x = 15, and int =y = 20, then int x - y = 0? I need this for my character's and enemy's health. I obviously don't want it to display -5 health.